In the wake of a dramatic RCMP reveal of two people arrested in Canada in connection with a plot to derail a passenger train, Canadians may have questioned why the United States Department of Homeland Security and the US Federal Bureau of Investigation were involved in the operation.

Those who have followed the quiet evolution of Canada-US cross-border policing, however, weren’t surprised. Law enforcement agencies in Canada and the US are now working together in an unprecedented way, says the RCMP—and the two countries are hammering out a plan to let agents in both countries drive back and forth across the border as though it wasn’t there.